Amberlite IR-120 resin

Aluminum isopropoxide, 35, 40 Amberlite IR-4B resin, 32, 13 Amberlite IR-120 resin, 37, 56 Amidation, of isocyanic acid with bromo-aniline and other aromatic amines, 31, 8... 

Hydrolysis of amides and hydrazides.1 Unsubstituted amides (RCONH2) are hydrolyzed to acids in refluxing water when mixed with a 15-fold excess of Amberlyst 15 or Amberlite-IR-120 resins generally in 90% yield. Esters are formed when an alcohol is used instead of water. Hydrazides are hydrolyzed more rapidly than amides under these conditions. 

Selected from numerous other, apparently randomly studied, reactions are carboxylation of menthol or menth-l-ene at C-l, C-3, C-4, and C-8 on treatment with C0-BF3-C1CH2C02H,412 coupling of limonene at C-2 and C-4 to xylenols in the presence of Amberlite IR-120 resin,413 dimerization (C-3 to C-3 linkage) of carvone induced by FeCl3,414 and the aromatization observed in the BF3-catalysed reaction of terpinolene and tetrahydrogeraniol to give cymen-8-yl tetrahydrogeranyl ether.415... 

Cyclization of costunolide. The acid form of Amberlite IR-120 resin was used for a cyclization under mild conditions of the costunolide (1), which polymerizes readily in the presence of strong acids, to a- and -cyclocostunolide, (2)... 

Methionine (7 .S-2-amino-4-methylthiobutyric acid) ]59-51-8] M 149.2, m 281"(dec), pKJ 2.28, pK 9.21. Crystallise it from hot water or EtOH. Also purify it by dissolving it in H2O and passing through an Amberlite IR-120 resin (NH4 form). The eluate is concentrated and then passed through Amberlite IR-4B resin, and this eluate is evaporated to dryness. The residue is washed with EtOH, then Me2CO, dried and recrystallised from aqueous EtOH (colourless plates) [Baddiley Jamieson J Chem Soc 4283 7954]. [Greenstein Winitz The Chemistry of the Amino Acids J. Wiley, Vol 3 p 2125 1961, Beilstein 4 IV 3190]... 

Both primary and secondary Boc-protected aliphatic amines can be purified and deprotected efficiently by treatment with Amberlyst 15 (catch-and-release technique) without causing any racemlzation (eq 4). Amberlite IR-120 resin can be used for deprotection of W-/>toluenesulfinyl-protected amines. ... 

Obtained by reaction of 2-methyl-2-buten-l-ol with phloropropiophenone in dioxane in the presence of Amberlite IR-120 resin (H form), first at 20° during 0.5 h, then at reflux for 24 h [7739],... 

Additionally, the opening of the epoxide with Amberlite IR-120 resin (H" ) produces methyl 2-acetamidogulopyranoside in 64% yield. 

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